Marcus Bartlett Giamatti[1][2] (born October 3, 1961) is an American actor, musician, writer and director.
He has also guest-starred on a number of popular series, such as The X-Files, Homicide: Life on the Street, Monk, The Mentalist, House M.D.
He has less frequently appeared in films, which include Mr. and Mrs. Bridge, Necessary Roughness, and the television docudrama Pirates of Silicon Valley.
Giamatti tossed the ceremonial first pitch at the 1989 World Series opener, played in Oakland, California.
From 2010–14, he has guest starred on series including Fringe, The Closer, Revenge, Bones and NCIS: Los Angeles.